1. Field of the Invention
The present invention relates to a touch display. More particularly, the present invention relates to a liquid crystal display (LCD) with a built-in touch panel having a good contrast and visibility.
2. Description of Related Art
FIG. 1 is a schematic diagram of a conventional LCD with a built-in touch panel. Referring to FIG. 1, the LCD 100 with a built-in touch panel includes an LCD panel 110 and a touch panel 120. The LCD panel 110 includes a first polarized plate 111, a lower substrate 112, an active device array 113, a liquid crystal layer 114, a common electrode layer 115, an upper substrate 116 and a second polarized plate 117. The touch panel 120 includes a first substrate 121, a lower electrode 122, a dielectric layer 123, an upper electrode 124 and a second substrate 125. Particularly, the touch panel 120 and the LCD panel 110 are adhered together via a double-sided adhesive 130. However, the double-sided adhesive 130 is only attached to peripheries of the LCD panel 110 and the touch panel 120. Therefore, an air layer 140 may be existed between the touch panel 120 and the LCD panel 110. Ambient lights (not shown) may be reflected by the air layer 140, which may lead to a decrease of contrast and visibility of the LCD panel 110.
FIG. 2 is a schematic diagram of another conventional LCD with a built-in touch panel. Referring to FIG. 2, the LCD 102 with a built-in touch panel is approximately the same as the LCD 100 with a built-in touch panel, and like reference numerals refer to the like elements throughout. The difference there between is that in the LCD 102 with a built-in touch panel, the LCD panel 110 and the touch panel 120 are adhered together via an optical adhesive 150. Since the optical adhesive 150 is fully coated between the LCD panel 110 and the touch panel 120, the LCD 102 with a built-in touch panel may not have a problem of interface reflection, and may have a good display effect. However, the optical adhesive 150 may have a poor reliability after long time utilization. Moreover, during assembling, air bubbles may be generated in the optical adhesive 150, which may lead to an abnormal scattering of light. Furthermore, utilization of the optimal adhesive 150 may have a problem of excessive overall thickness, and is uneasy to rework when sticking quality thereof is poor. More particularly, if the touch panel 120 is damaged and the LCD panel 110 functions well, it is difficult to replace the touch panel 120.
FIG. 3 is a schematic diagram of still another conventional LCD with a built-in touch panel. Referring to FIG. 3, the LCD 104 with a built-in touch panel is approximately the same as the LCD 100 with a built-in touch panel, and like reference numerals refer to the like elements. The difference there between is that the LCD 104 with a built-in touch panel includes an antireflection film 160 disposed at a side of the touch panel 120 facing to the LCD panel 110, and the LCD panel 110 and the touch panel 120 are still adhered together via the double-sided adhesive 130. Therefore, the problem of the interface reflection of the LCD 104 with a built-in touch panel may be avoided, and reworking capability thereof is rather good.
However, cost of the antireflection film 160 is relatively high. Moreover, during assembling of the antireflection film 160, problem of contamination or poor adhesion of the antireflection film 160 caused by peripheral adhesive residues (not shown) may occur.